Posted
by
Unknown Lamer
on Wednesday October 16, 2013 @10:33AM
from the aliens-inside dept.

MancunianMaskMan writes "The BBC writes about the meteorite that fell from the sky 8 months ago: 'The object plunged into Lake Chebarkul in central Russia on 15 February, leaving a 6m-wide hole in the ice. Scientists say that it is the largest fragment of the meteorite yet found.'"
This is one of the ten largest meteorite fragments ever recovered. Unfortunately, it broke into three pieces after being lifted from the lake, and managed to destroy the scale used to weigh it when it hit 570kg.

From The Hitchhiker's Guide to the Galaxy: "Space," it says, "is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space, listen..."

Actually, if you read the manual, soviet russia "jokes" stopped being an obligation when taco left. None the less, given the subject of the story I calculate the overused meme will appear in 51% of all comments. Carry on, comrades.

Of course we read it. Usually twice. Then we fix it, send a note to the manufacture with correct instructions, then use whatever it is the manual was for. Now you geeks like to blow off the manual, and then whine about the device and how its no good becasue you don't understand it. Nerd on the other hand, actually like to know what they are doing.

"Scientists were initially baffled with reports that the meteorite fragments were hollow, but after arriving at the site stated that this was in fact completely normal as was the trail of slime leading into the nearby forest. Russian military sources state that the ongoing training exercises in this forest are completely unrelated."

There is a picture in that article of someone measuring a smaller fragment with some calipers. Is this how scientists measure rocks? It looks like they are only measuring the length of a portion of the rock because the calipers are too shallow to allow complete enclosure.

The point is similar to place a coin next to something when you take a picture. To give scale.They could have mentioned the surface area in football fields but the size of the rock didn't fit that unit that well.

It wouldn't surprise me if they took another picture without the calipers first before they realized that there was no way for the viewer to get a sense of the size of the object.

The object was weighed suspended from a scale clearly visible at 00:36 in the linked BBC video. The video does not show if the failure was the scale mechanism itself or the collapse of the A-frame/pulley it was suspended from.

After reading the summary and scanning the article (in true Slashdot fasion!) I went to look at the comments... and they are all complete drivel. Tons of stupid jokes and no actual discussion of the event. What the hell has happened here??

Anyway - back on topic: Does anyone else feel like that rock is WAY too big to have only left a 6m hole in the ice? That rock impacting the ice/water would have been an enormous event... it would have vaporized a ton of water and blown the ice away for at least several hundred feet.

I felt the same. Then I stopped caring. Well, rather, so far they've retrieved 20+ 'fragment' of 'something' yet only 4-5 were confirmed to be from a meteor. Let's wait till they confirm that this one was or wasn't before wondering what's going on =)

This is why I wanted to see the discussion - because my own intuition (which I totally agree is not based on any real world experience of such an event) led me to think that the ice hole wasn't right. Unfortunately, everyone was too damn busy making Soviet Russia meme jokes to actually talk about the physics involved...

But - we've now been able to have a bit of good discourse here in this thread and my understanding has definitely increased from the po

Not necessarily. The fact that it broke into two pieces as it passed over Chelyabinsk (watch the videos of the event, there were two large sonic booms, hence two large pieces) implies that it had already been melted down quite a bit. And, yes, there were two large pieces; one of the online videos I've seen (one of the ones taken with a dashboard camera) clearly shows two large flareups.

The rock would have been at terminal velocity, which is typically less than 200 meters/sec (see here), since it has been slowed by the atmosphere. It's not landing in the lake at cosmic velocities (which would indeed be quite dramatic).

Using the standard car analogy, imaging dropping a car into the ice from a skyscraper conveniently located next to the ice. The car would not obliterate huge amounts of ice and vaporize large amounts of water -- it'd punch a somewhat-larger-than-car-sized hole in the ice.

Cool - I'm ok with that - that's why I came here to see some discussion;-)

Mind providing some insight on why it wouldn't have? The car "analogy" above does give a good "feel" for why that hole wouldn't have been larger (although the terminal velocity of a rock would be somewhat higher than a car).